APPENDIX. 353 



and two oblique lines upon the scutel, yellow; wings iuVi- 

 ginous ; feet blackish, with dull rufous joints, and tarsal 

 hair ; anterior feet before dull rufous ; tergum, bands yel- 

 low, not at all emarginated each side, the basal band wide- 

 ly interrupted, second band less widely interrupted, the 

 penultimate one hardly interrupted, and the ultimate one 

 entire. 



Length about seven-twentieths of an inch. 



That these three species are congeneric is evident, but 

 they do not correspond in all respects with the genus Me- 

 GACHiLE as defined by ei^tomologists. The trophi agree 

 very well, and the form of the nails of the feet in the two 

 sexes are also similar, but the tergum is convex, as in 

 OsMiA, and the abdomen curves very much downwards 

 towards the tip, as in Stelis, from which latter genus they 

 differ by having a hairy venter. 



CAELIOXYS, Lafr. 



C. 8-dentafa. Black ; abdomen with five white bands, 

 tip eight-toothed. 



Inhabits United States. 



% Front and hypostoma with dense, long, dull yellow- 

 ish hair ; thorax with a dentated band before, interrupted 

 in the middle, a spot at the base of the wings and a trans- 

 verse line at base of the scutel, white ; wings a little dusky 

 on the apicial margin ; feet rufous ; tergum with five white 

 bands, of which the two or three terminal ones are double; 

 segments each with a transverse indented line ; tip with 

 eight teeth, of which two are on each side, and four at the 

 extremity placed two above and two beneath ; venter with 

 a white line on the posterior margin of each segment, the 

 basal and terminal ones obsolete. 



